1. Field of the Invention
The present invention in general relates to a lighting device, in particular, to a bulb-type LED lamp and a cooling structure thereof.
2. Description of Prior Art
Common incandescent bulb takes tungsten filament as lighting source, so the structure is simple, and the arrangement and exchange therefor are very convenient. In the structure of an incandescent bulb, a tail end of the spherical shade is usually fixedly connected an adapter, on which there are threads adapted to be screwed in a common bulb socket. When power is conducted, the tungsten filament arranged in the shade can emit heat and light, and the light shines outwardly via the shade to reach a lighting purpose. However, during the operation when the tungsten filament generates illuminating light, a large amount of heat is also generated. Therefore, this kind of lighting device is very power-consuming and energy wasting, and has very short lifespan because the tungsten filament is easily burned to black out the incandescent bulb.
LED, a kind of lighting source in solid state, can transfer electricity into light. In the meantime, LED has the merits of small size, low driving voltage, quick reaction speed, vibration resistance and long lifespan. Besides, following the continuity of development and progress of technology, the trend of electronic component is toward compactness, such that the bulb-type LED lamp has gradually replaced the incandescent bulb to become a lighting device that is applied in large amount and comprehensively.
According to prior arts, a bulb-type LED lamp mainly includes a circuit board, a plurality of LEDs electrically connected to the circuit board, a transparent shade covering each LED, an aluminum-extruded cooling seat attached by the circuit board and an adapter fixed to the aluminum-extruded cooling seat. However, since the cooling efficiency of the aluminum-extruded cooling seat is decided by the surface area thereof, and because the surrounding air can only make heat exchange with the surface of the aluminum-extruded cooling seat, the cooling efficient is limited and the cooling speed is slow, further influencing the working performance of this kind of bulb-type LED lamp.
Accordingly, after a substantially devoted study, in cooperation with the application of relative academic principles, the inventor has finally proposed the present invention designed reasonably to possess the capability to improve the drawbacks of the prior arts significantly.